Implementation of two high through-put techniques in a novel application: detecting point mutations in large EMS mutated plant populations

Background  

The establishment of mutant populations together with the strategies for targeted mutation detection has been applied successfully to a large number of organisms including many species in the plant kingdom. Considerable efforts have been invested into research on tomato as a model for berry-fruit plants. With the progress of the tomato sequencing project, reverse genetics becomes an obvious and achievable goal.     

Moroccan crustal response to continental drift

The refercnce to Bouguer anomalies in the caption to Fig. 2 of the report by W. H. Kanes et al. (Science, 1 June 1973, p. 950) is in error. Isostatic anomalies are meant.-Ed.     

Butterfly feeding on lycopsid

Larvae of Euptychia westwoodi feed on Selaginella, a lycopsid. This is the first feeding record in the Satyrinae outside the monocotyledons and one of the few records of a butterfly feeding on other than a seed plant. Clues to possible evolutionary origins of this habit are found in the oviposition behavior of other Euptychia species.     

Procollagen: conversion of the precursor to collagen by a neutral protease

An enzymatic activity (procollagen peptidase), capable of converting the biosynthetic precursor procollagen to collagen at neutral pH, has been identified in rat and chick calvarial bone. Limited proteolysis of procollagen with chymotrypsin resulted in a similar transformation. The activity in bone can be demonstrated in vitro despite inhibition of new collagen synthesis by cycloheximide. Preservation of the collagen precursor in preparations extracted with acetic acid results from inhibition of the enzymatic activity at low pH.     

Ecology. The value of nature and the nature of value

Ecosystems are capital assets: When properly managed, they yield a flow of vital goods and services. Relative to other forms of capital, however, ecosystems are poorly understood, scarcely monitored, and--in many important cases--undergoing rapid degradation. The process of economic valuation could greatly improve stewardship. This potential is now being realized with innovative financial instruments and institutional arrangements.     

Platelet-activating factor-induced aggregation of human platelets specifically inhibited by triazolobenzodiazepines

Platelet-activating factor (PAF), a naturally occurring phospholipid, is a potent activator of various biological processes, including platelet aggregation. The mechanisms by which PAF acts are largely unknown, partly because of the lack of specific inhibitors for PAF-elicited responses. It was found that in washed human platelets the psychotropic triazolobenzodiazepine drugs alprazolam and triazolam potently inhibited PAF-induced changes in shape, aggregation, and secretion. The effects were specific for PAF activation, since the responses of human platelets to adenosine diphosphate, thrombin, epinephrine, collagen, arachidonate, and the calcium ionophore A23187 were not inhibited by the triazolobenzodiazepines. These psychotropic drugs should be useful in investigating the possibility that PAF or PAF-like phospholipids play a role in neuronal function and in elucidating biochemical mechanisms activated specifically by PAF in a variety of cells.     

Plant-herbivore coevolution: lupines and lycaenids

Predation on lupine flowers by larvae of a lycaenid butterfly was studied by comparison of inflorescences exposed to and protected from infestation, and by comparison of lupine populations exposed to different degrees of attack. The lycaenids caused striking reduction in seed set, indicating that this small herbivore could act as a potent selectie agent in lupine populations.